package cn.com.homework;

import java.util.HashSet;
import java.util.Set;
import java.util.TreeSet;

public class Test3 {

	public static void main(String[] args) {
		Set<String> s = new HashSet<String>();
		s.add("a");
		s.add("b");
		Set<String> s1 = new TreeSet<String>();
		s1.addAll(s);
		for (String str : s1) {
			System.out.println(str);
		}
	}
}
